Refrigeration compressors in general and more specifically, refrigeration compressor of the hermetically sealed reciprocating piston type normally include a reservoir of lubricating oil in the lower portion or sump of the sealed shell. A pump of some type is normally provided which operates to circulate oil to the bearings and other components requiring lubrication through oil passages which extend through the compressor's crankshaft. Because the oil is in open communication with the refrigerant of the compressor, it is not uncommon for some of the refrigerant in liquid and/or gaseous form to become mixed with the oil. As the operation of the compressor heats the lubricating oil, a portion of this mixed liquid refrigerant will be boiled off. It is therefore important to have the crankshaft's lubrication passages incorporate a vent of some type to avoid vapor lock which could stop the flow of lubricating oil to the bearings. Additionally, it is also generally desirable to minimize the amount of the intermixing of the lubricating oil and the refrigerant gas at suction pressure flowing to the intake of the compressor in order to prevent slugging of the compressor as well as preventing the carry over of oil into the refrigeration system.
Accordingly, the present invention provides an improved lubrication system which incorporates fluid passages within the crankshaft to effectively vent any gaseous refrigerant from the lubrication oil flowing through the passages yet still ensuring that no lubricating oil is carried over into the primary flow area for the refrigerant at suction pressure to the intake of the compressor. The lubrication system of the present invention ensures full and complete lubrication of all bearing surfaces and the like over a wide range of operating conditions of the compressor.
Other advantages and objects of the present invention will become apparent to those skilled in the art from the subsequent detailed description, appended claims and drawings.